The present disclosure relates to a turbo fan and a ceiling type air conditioner using the same.
In general, ceiling type air conditioners are apparatuses which are buried into an indoor ceiling to introduce indoor air and discharge heat-exchanged air into an indoor space. In such a ceiling type air conditioner, air may be suctioned through a suction hole defined in a center of the air conditioner, and the suctioned air may be air-conditioned by a heat exchanger disposed within the ceiling type air conditioner. The air-conditioned air may be discharged into the indoor space through a discharge part disposed on an edge of the ceiling type air conditioner to adjust a temperature and humidity in the indoor space.
FIG. 1 is a cross-sectional view illustrating an inner structure of an indoor unit of a ceiling type air conditioner according to a related art.
Referring to FIG. 1, an indoor unit 10 of the ceiling type air conditioner according to the related art may include a case 20 installed in a ceiling and a turbo fan 30 accommodated in the case 20 and having a plurality of blades 31. The turbo fan 30 may be operated by a motor 32 that provides power. The motor may be attached to a predetermined plate (not shown) to operate the turbo fan 30.
Also, the turbo fan 30 may include an orifice 17 guiding indoor air so that the indoor air is suctioned into the turbo fan 30 and a shroud 50 guiding the air passing through the orifice 17 into a heat exchanger 40.
A gap 15 may be defined between the shroud 50 and the orifice 17. When an amount of air passing through the turbo fan 30 is greater than that of air to be discharged into the indoor space, the air may be suctioned again into the turbo fan 30 through the gap 15.
A suction hole 90 for suctioning the indoor air may be defined in a center of the indoor unit 10, and a plurality of discharge holes 60 may be defined outside the suction hole 90.
When the indoor unit 10 is operated for a predetermined time, the motor 32 may increase in temperature. Thus, a cooling passage 80 having a predetermined distance may be defined between the turbo fan 30 and a bottom surface of the case 20.
Hereinafter, an operation of the ceiling type air conditioner according to the related art will be described.
When the indoor unit 10 of the ceiling type air conditioner is operated, the motor 32 may be operated to operate the turbo fan 30. Also, the indoor air suctioned through the suction hole 90 may be suctioned into a central portion of the turbo fan 30 by the operation of the turbo fan 30. Here, the orifice 17 may guide the indoor air suctioned through the suction hole 90 so that the indoor air is suctioned into the central portion of the turbo fan 30.
The suctioned indoor air may be heat-exchanged through the heat exchanger 40 disposed on a circumference of the turbo fan 30. That is, the air introduced into the turbo fan 30 may be guided into the heat exchanger 40 by the shroud 50.
Also, the heat-exchanged air may be supplied into the indoor space through the plurality of discharge holes 60 defined outside the suction hole 90.
However, a speed of the air passing through an upper portion of the heat exchanger 40 and a speed of the air passing through a lower portion of the heat exchanger 40 may be different from each other with respect to the center of the heat exchanger 40. That is, according to characteristics of the ceiling type air conditioner, since the motor 32 of the indoor unit 10 is attached to the ceiling, the turbo fan has to be fixed to an upper end of the ceiling type air conditioner. Thus, a speed of the air passing through the upper portion of the heat exchanger 40 may be greater than that of the air passing through the lower portion of the heat exchanger 40.
That is to say, a speed of the air passing through a lower portion of the turbo fan 30 may be relatively less than that of the air passing through an upper portion of the turbo fan 30. Thus, the air passing through the lower portion of the turbo fan 30 may not pass through the heat exchanger, but drop down.
The air dropping down may pass through the gap 15 defined between the shroud 50 and the orifice 17 and then be suctioned again into the turbo fan 30.
However, if an amount of air passing through the gap 15 exceeds a predetermined value, an amount of air passing through the discharge hole 60 may decrease. Thus, the whole system may be deteriorated in efficiency. In addition, a flow loss of the air may cause degradation in performance of the turbo fan 30.